Stepping switch



STEPPING SWITCH Filed June 2, 1958 3 Sheets-Sheet 2 INVENTOR.

(Zara/ice J/r/pac/z ENZ w H/S ATTORNEY July 4; 1961 Q HOLPUCH 2,990,723

STEPPING SWITCH Filed June 2, 1958 3 Sheets-Sheet 3 INVENTOR. ('h/ezzceJ766w ZMZ/ZM HIS ATTORNEY United States Patent 2,990,723 r STEPPINGSWITCH; Clarence J. Holpuclr, Chicago, 11]., asslgnor to AdmiralCorporation, Chicago, 111., a corporation of Delaware Filed June 2,1958, Ser. No. 739,324 2 (Cl. 74-142) This invention relates, generally,to stepping switches, and more particularly to a simplifiedelectromagnetic stepping switch of the type employing a ratchet wheeland a pawl.

There are, in the prior art, many diflerent types of electromagneticstepping switches using a relay, a pawl operated by the relay, and aratchet wheel operated by the pawl. It is desirable, ordinarily, toaccomplish three dilferent functions with respect to the ratchet Wheel.Firstly", it is desirable to rotate the ratchet wheel a certain angulardistance by means of the pawl in response to a single input signalsupplied tothe relay. Secondly, it is desirable to prevent the ratchetwheel from overshooting', the desired angular distance due tothemomentum imparted thereto" by the action of the pawl. Thirdly, it isdesirable to prevent backlash of the ratchet wheel when the pawl isdisengaged therefrom. These three functions ordinarily are performed byseparate and distinct structures. For example, the backlash preventingfunction often is performed by means of a flat spring member secured atone end and having its free end resting against the toothed edge of theratchet wheel. The rotation of the ratchet wheel usually is produced bythe action of the pawl which can be affixed to the relay armature, andthe overshoot prevention function is produced sometimes by dampingmeans, or sometimes even omitted.

Now it is a primary of the present invention to provide a steppingswitch in which the rotation of theratchet wheel and the means forpreventing overshoot are integral with the relay armature.

Another object of the invention is to provide a simple means forpreventing overshoot of the ratchet wheel.

Other objects of the invention are to provide a simple, reliable, andinexpensive stepping switch and in general to improve stepping relays.

In accordance with the invention, there is provided a supporting frame,a relay winding means mounted upon said supporting frame, and a relayarmature positioned across one end of saidrelay winding means andloosely and pivotally mounted at one end thereof upon said supportingframe to: permit pivoting in limited arcs towards and away and from thewinding means and also transversely to the winding means. The said relayarmature is constructed to have first. and second pawls formed Iintegrally therewith at the. other end thereof. First spring means areprovided to bias thev armature away from the winding means and in. afirst transverse position. A ratchet: wheel is constructed and arrangedto be engaged by said first pawl in response to the movement of thearmature toward said winding. to rotate a. predetermined angulardistance.

The said second pawl is constructed and arranged to engage said ratchetwheel after said first pawl has caused rotation thereof a predeterminedangular distance to prevent: further rotation. thereof. Second springmeans. are constructed to engage the ratchet wheel. to prevent blacklasthereof.

Important features of the invention. are the formation of the first pawlintegrally with the. armature and the loose mounting of the armature topermit said first pawl to ride around the perimeter of the ratchet wheelas it rotates. Another important feature of the invention is theformation of the second pawl integrally with the armature. Thelast-mentioned feature constitutes a subcombination, as" follows.

In accordance with another form of the invention, the armature can bemounted at one end thereof to pivot in one plane only. The first pawl isof a spring material in order to follow the perimeter of the ratchetwheel as said wheel rotates. The said second pawl is formed integrallywith the armature and functions, as described supra, to limit the amountof rotation of the ratchet wheel.

The above-mentioned and other objects and features of the invention willbe understood more fully when read in conjunction with the drawings, inwhich:

FIG. 1 shows a perspective view of the invention; FIG. 2 shows a planview of the top of the structure 'of'FIG. 1;

FIG. 3 shows a plan view taken along the plane 3-3 of FIG. 1;

FIGS.- 4 and 4a show partial plan views of the stepping switch takenalong the plane 4-4 of FIG. 1, and

FIGS; 5 and 6 show partial plan views of an alternative form of theinvention and employing a relay armature mounted at one end so as to bepivotal in one plane only and having a flexible pawl for rotating theratchet wheel.

It is to be noted that throughout the several figures shown herein,similar elements will be identified by the same reference character,although primed in succeeding figures;

Referring now to FIG. 1, the coil wound relay winding 10- is mounted ona bracket or supporting means 11, which in turn is mounted on anotherbracket or supporting means 12. A core 13 of magnetic material extendsbeyond the upper end of the winding 10. An armature 14, having two pawlelements 15 and 16 thereon, is actuated by the relay winding 10 and thecore 13-. More specifically, when the winding 10 is de-energized thearmature 14 is caused to be in its up position by the action of tensionspring 21, as shown in FIG. 1, and when the winding 10 is energized thearm 14 is magnetically drawn to the bar 13 and assumes its downposition. (See FIGS. 4 and 4a.) The arm 14 is pivoted loosely on thebracket 11 between the legs 17 and 18, so that the arm 14 can move notonly up and down, but can also move sidewise with respect to the axis ofwinding 10'. Such sidewise motion is important, since it permits thepawl 15 to ride with the ratchet wheel 37, as said ratchet wheel iscaused to rotate due to the pawl 15 being forced ilown upon it. Thisaction will be described in detail ater.

Returning now to the pivoting means for the arm 14, reference is made toFIGS. 2 and 3. In FIG. 2, which is a top view of FIG. 1, the lateralpositions of the arm 14' are shown when the arm 14 is in its up position(solid line) and when the arm is in its down position (dotted line). Itcan be seen that the notches 19 and 20 in the arm 14' are suflicientlylarge to permit the sidewise (or lateral) motion necessary to theoperation of the device. As indicated herein before, when the winding isde-energized the arm 14' is caused to assume its up position (as shownby the solid line in FIG. 2) due to the action of the tension spring21', which is shown more clearly in FIG. 3.

More particularly, it can be seen that one end of spring .21" is securedto the arm 14" near the end thereof by some convenient means, such asthe narrowed portion 22' of said arm. The other end of the spring issecured to the bracket 23", which in turn is secured to the bracket 11".It will be apparent that the spring 21" exerts a vertical force F and alateral force F upon the end of the arm 14" to cause the arm 14 toassume the solid line position of FIG. 2 when inits' up'position.

Referring now to FIGS. 4 and 4d, the action of the arm 14 with respectto the ratchet wheel will be discussed. In FIG. 4, the arm is shown inits up position. The spring 25 prevents the wheel 37" from backlash,which this case would be rotation in a clockwise direction, but doespermit rotation in a counterclockwise direction. In FIG. 4a the arm 14"is shown in its down position. tion of FIG. 4.) During the course ofassuming its down position the pawl engages the gear tooth 28 of theratchet wheel and rotates said wheel through a small angular distance(about 27'V2). It will be observed that the pawl 15", and thus the arm14"" are forced laterally to the left in FIG. 4a, as the wheel 37" isrotated. To prevent any rotation greater than 27%, the pawl -16.comes torest on the gear tooth 29 in the down position of arm 14". To preventbacklash the spring 25" comes to rest under the tooth 31'.

When the winding 10 is de-energized the arm 14"" will again assume itsup position.

It is to be noted that the lateral excursion of the arm 14' to the left(see FIGS. 2 and 3) is limited by the portion 30 of the bracketstructure 11'.

Referring again to the structure shown in FIG. 1, it can be seen thatthe ratchet wheel is mounted on a shaft 33, which in turn is rotatablysupported on a contact holding plate 34. The contact holding plate 34 ismounted securely on the frame structure 12 by suitable means such asbolts 39. A sweep contact 32, which rotates with the ratchet wheel 37 issecured to the end of the shaft 33, and makes contact with consecutiveones of the equally spaced contacts 35. Adjacent ones of con- (Thedotted line position shows the up posia scribed herein are but preferredembodiments of the invention and that various changes may be made intheir design without departing from the spirit or scope thereof.

I claim:

1. A ratchet relay comprising, a supporting frame, electromagnet meansmounted on said frame and having a determinable first axis, an armaturemounted for pivotal movement about a fixed second axis and for furthersimultaneous pivotal movement laterally of said first axis, a ratchetwheel rotatably mounted on said frame for rotation about a third axisperpendicular to both said first and said second axes, saidelectromagnet means when energized applying a force to said armaturethat is radially toward said ratchet wheel, a pair of pawls integrallyformed with said armature, each of said pawls disposed laterally of saidthird axis with one pawl on one side of said third axis and the otherpawl on the other side of said third axis, said pawls being displacedfrom one another at their extremities by a distance greater than theradius of said ratchet wheel and less than the diameter of said wheel,one of the pawls being longer than the other for initial engagement withsaid ratchet wheel to rotate the latter a predetermined angular distanceupon pivotal movement toward said wheel, the other of said pawls beingsubsequently engageable with said ratchet wheel and cooperating withsaid one pawl to stop said ratchet wheel upon rotation through saidpredetermined angular distance, said pivotal movements of said armautrepermitting said pair of pawls to follow the periphery of said ratchetwheel, said frame being of U-shaped configuration having an elongatedflat recess in the end of one leg and a subto said armature outside saidone leg of said frame for tacts 35 are spaced apart angular distancesequal to the angular distances between adjacent teeth on the ratchetwheel 37. Leads such as leads 36 connect the contacts 35 to individualones of the terminals 38 located at the edge of the plate 34. It is tobe noted that the plate 34 may be a printed circuit board or any othersuitable contact bearing plate.

Referring now to FIGS. 5 and 6, there is shown a modification of theinvention. In FIG. 5, the armature 14a has fingers 42 formed thereonwhich fit into apertures provided therefor in mountings 41 and 43. Themountings 41 and 43 are secured to, or are part of, the generalsupporting structure 11 of FIG. 1. It can be seen that the arm 14a willpivot substantially only in one plane, e.g., in a plane perpendicularboth to the line formed by the fingers 42 and the plane of the paper onwhich FIG. 5 is drawn. However, with such a pivoting arrangement, it isobvious that a rigid pawl such as pawl 15 of FIG. 1 cannot be employedtherewith since such a pawl would be unable to ride around the perimeterof a ratchet wheel as the ratchet wheel rotated. The solution to theaforementioned problem is a flexible pawl, such as the pawl 44 shown inFIG. 6, which is secured to the armature 14a and which can ride aroundwith the ratchet wheel 37a. In FIG. 6 the dotted line structure showsthe up position of the arm 14a and the solid line structure shows thedown position of the arm 14a. Spring 25a functions to prevent backlashof the wheel 37a.

' It is to be noted that the structures shown and deurging said armatureinto bearing contact with said recess and against the upper portion ofsaid window.

2. A ratchet relay comprising, a supporting frame, electromagnet meansmounted on said frame and having a determinable first axis, an armaturemounted for pivotal movement about a fixed second axis and for furthersimultaneous pivotal movement laterally of said first axis, a ratchetwheel rotatably mounted on said frame for r0- tation about a third axisperpendicular to both said first axis and said second axis, saidelectromagnet means when energized applying a force to said armaturethat is radially toward said ratchet wheel, a pair of pawls integrallyformed with said armature, each of said pawls disposed laterally of saidthird axis with one pawl on one side of said third axis and the otherpawl on the other side of said third axis, said pawls being displacedfrom one another at their extremities by a distance greater than theradius of said ratchet wheel and less than the diameter of said wheel,one of said pawls being longer than the other for initial engagementwith said ratchet wheel to rotate the latter a predetermined angulardistance upon pivotal movement toward said wheel, the other of saidpawls being subsequently engageable with said ratchet wheel andcooperating with said one pawl to stop said ratchet wheel upon rotationthrough said predetermined angular distance, said pivotal movements ofsaid armature permitting said pair of pawls to follow the periphery ofsaid ratchet wheel, said frame being of U- shaped configuration havingan armature engaging portion in the end of one leg for engagement ofsaid armature in a manner to allow said pivotal movement about saidfirst and'said second axes, and a stop portion overlying the top of saidarmature near said other leg, said armature extending between the end ofsaid other leg and said stop portion near its pawl end and overhangingsaid one leg near its pivot end, and a spring angularly disposedrelative to said first axis for applying simultaneously restoringpivotal movement forces to said armature laterally of said first axisand about said fixed second 5 axis to return said armature to itsinitial position upon References Cited in the file of this patent UNITEDSTATES PATENTS Messiter June 24, Fuller Mar. 14, Barth Feb. 10, ObszarnyJuly 6, Henninger et al. July 3,

FOREIGN PATENTS Great Britain May 5,

